铂树状大分子包裹氧还原电催化剂的原位结构表征。

In situ structural characterization of platinum dendrimer-encapsulated oxygen reduction electrocatalysts.

机构信息

Department of Chemistry and Biochemistry, Center for Electrochemistry, Texas Materials Institute, Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, 1 University Station, A5300, Austin, Texas 78712-0165, USA.

出版信息

Langmuir. 2012 Jan 17;28(2):1596-603. doi: 10.1021/la203756z. Epub 2012 Jan 5.

DOI:10.1021/la203756z

PMID:22221003

Abstract

In situ electrochemical extended X-ray absorption fine structure (EXAFS) was used to evaluate the structure of Pt dendrimer-encapsulated nanoparticles (DENs) during the oxygen reduction reaction (ORR). The DENs contained an average of just 225 atoms each. The results indicate that the Pt coordination number (CN) decreases when the electrode potential is moved to positive values. The results are interpreted in terms of an ordered core, disordered shell model. The structure of the DENs is not significantly impacted by the presence of dioxygen, but other electrogenerated species may have a significant impact on nanoparticle structure.

摘要

原位电化学扩展 X 射线吸收精细结构（EXAFS）被用于评估铂树状大分子包裹纳米粒子（DENs）在氧还原反应（ORR）过程中的结构。DENs 每个平均仅包含 225 个原子。结果表明，当电极电势向正值移动时，Pt 的配位数（CN）降低。这些结果可以用有序核、无序壳模型来解释。DENs 的结构不受氧气存在的显著影响，但其他电生成的物种可能对纳米颗粒结构有重大影响。